I have the game in m Xbox 360 right now and unfortunately, it's only 1 disc. I say unfortunately, because if it were 2, then it would be good content like HD packs and such. So it seems to be pretty small...

Ok thanks. I have a 4GB X-Box Slim with an extra 20GB HDD. I've been worried all day about whether I'd be able to play the game at launch or not, due to rumors of the install being around 20GB. I'm glad to hear this. Thanks.